External facing communications for autonomous vehicles

ABSTRACT

Aspects of the disclosure provide for displaying notifications on a display of an autonomous vehicle. In one instance, a distance from the vehicle to a destination of the vehicle or a passenger may be determined. When the distance is between a first distance and a second distance, a first notification may be displayed on the display. The second distance may be less than the first distance. When the distance is less than the second distance, a second notification may be displayed on the display. The second notification provides additional information not provided by the first notification.

BACKGROUND

Autonomous vehicles, for instance, vehicles that do not require a humandriver, can be used to aid in the transport of passengers or items fromone location to another. Such vehicles may operate in a fully autonomousmode where passengers may provide some initial input, such as a pickupor destination location, and the vehicle maneuvers itself to thatlocation. Autonomous vehicles are equipped with various types of sensorsin order to detect objects in the surroundings. For example, autonomousvehicles may include sonar, radar, camera, LIDAR, and other devices thatscan and record data from the vehicle's surroundings.

When a person (or user) wants to be physically transported between twolocations via a vehicle, they may use any number of taxi services. Todate, these services typically involve a human driver who is givendispatch instructions to a location to pick up and drop off the user. Inaddition, human drivers are able to communicate with the use of physicalgestures (hand, head, facial), a phone call, or an in-person discussionbetween the driver and the passenger. Autonomous vehicles, however, maynot always have a human driver who can make such communications.

BRIEF SUMMARY

Aspects of the disclosure provide a method of displaying notificationson a display of an autonomous vehicle. The method includes determining,by one or more processors of the vehicle, when the vehicle is between afirst distance and a second distance of a location, the location being adestination for the vehicle or a location of a passenger; when thevehicle is determined to be between the first distance and the seconddistance of the location, displaying, by the one or more processors, onthe display a first notification, the second distance being less thanthe first distance; determining, by one or more processors of thevehicle, when the vehicle is less than the second distance from thelocation; and when the vehicle is determined to be less than the seconddistance from the location, displaying, by the one or more processors,on the display a second notification, wherein the second notificationprovides additional information not provided by the first notification.

In one example, the first notification includes a color which identifiesthe vehicle to the passenger. In another example, the first notificationdoes not include alphanumeric characters. In this example, the secondnotification includes the color with alphanumeric characters, whereinthe alphanumeric characters provide the additional information. Inaddition or alternatively, the second notification includes the colorwith one or more icons, wherein the one or more icons provide theadditional information. In another example, the distance is the distanceto the passenger, and wherein the distance is determined based onlocation information determined at a client computing device of thepassenger. In another example, the first notification is brighter thanthe second notification. In another example, the second notification isbrighter than the first notification. In another example, the methodalso includes determining a brightness of the first or the secondnotification based on the distance, and displaying the firstnotification is further based on the brightness. In another example, themethod also includes determining a brightness of the first notificationor the second notification based on current traffic conditions, anddisplaying the first notification is further based on the brightness. Inanother example, the method also includes determining a brightness ofthe first or the second notification based current weather conditions,and displaying the first notification is further based on thebrightness. In another example, displaying the first notification isfurther based on a current speed of the vehicle. In another example,displaying the second notification is further based on a current speedof the vehicle. In another example, the method also includes determiningone or both of the first or second distances based on context in whichthe vehicle is driving. In this example, the context includes a currentspeed of the vehicle. In addition or alternatively, the context includesa number of passengers waiting for a pickup. In addition oralternatively, the context includes a number of vehicles picking up ordropping off a passenger. In addition or alternatively, the contextincludes current traffic conditions. In another example, the method alsoincludes receiving a request to change the display of the first or thesecond notification. In this example, the method also includes, inresponse to the request, flashing the display. In another example, themethod also includes, in response to the request, increasing abrightness of the display.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a functional diagram of an example vehicle in accordance withan exemplary embodiment.

FIG. 2 is an example of map information in accordance with aspects ofthe disclosure.

FIG. 3 is an example external view of a vehicle in accordance withaspects of the disclosure.

FIG. 4 is a pictorial diagram of an example system in accordance withaspects of the disclosure.

FIG. 5 is a functional diagram of the system of FIG. 4 in accordancewith aspects of the disclosure.

FIG. 6A-6C is example representations of first and second distances andfirst and second notifications in accordance with aspects of thedisclosure.

FIG. 7 is an example of a vehicle following a route in accordance withaspects of the disclosure.

FIG. 8 is an example flow diagram in accordance with aspects of thedisclosure.

DETAILED DESCRIPTION Overview

The technology relates to communicating information to persons,potential passengers and others, outside of an autonomous vehicle. Forvehicles with human drivers, there are ways to communicate with the useof physical gestures (hand, head, facial). Autonomous vehicles, however,may not always have a human driver who can make such communications.Thus, the features described herein may enable an autonomous vehicle tocommunicate with persons outside of the vehicle. To do so, informationmay be presented on a display which may be mounted at various locationson the vehicle, such as a display mounted at the center of a dashboardof the vehicle and oriented outwards, a display mounted on the roof, orat some other portion of the vehicle. In some instances, the display maybe flat, curved or even 360 degrees.

Moreover, information provided on the display can be contextually-awareof the vehicle's environment. For instance, the vehicle's varioussystems may provide a notification based on information such as time ofday, weather, level of traffic congestion, location of objects, as wellas other social and situational information about the vehicle'senvironment. The notification system may then dynamically adjust theinformation accordingly. This may even involve adjusting informationappropriately to increase legibility and comprehension of a message.

In one example the context and content of information displayed on thedisplay may be determined based on a distance (in time and/or space) toa pickup location for a passenger or a distance to a passenger of thevehicle as well as related considerations. The vehicle's computingdevices may determine whether the destination or the passenger isgreater than a second distance to the destination or the passenger butwithin a first distance to the destination or the passenger. When thevehicle is between these two distances to the destination or thepassenger, the vehicle may display a first notification on the display.

The vehicle's computing devices may determine whether the distance tothe destination or the passenger within the second distance to thedestination or the passenger. At distances within the second distance,the vehicle may display a second notification on the display. Thissecond notification may include aspects of the first notification, butmay also provide additional information such as text (includingalphanumeric characters), images, icons or other details which thepassenger can use to identify whether the vehicle has been assigned tothe passenger.

The first and second distances may be fixed values or may be adjustedbased on the context in which the vehicle is currently driving. Forinstance, the first and/or second distances may be increased ordecreased depending on the speed of the vehicle, the number of otherpedestrians or passenger waiting for a pickup nearby, and/or the numberof other vehicles (which may or may not be a part of a fleet ofautonomous vehicles attempting to pick up or drop off passengers).

The features described herein may enable an autonomous vehicle tocommunicate with persons outside of the vehicle. In particular, thefeatures described herein may allow a vehicle to display information inorder to better enable those passengers to recognize the vehicle in away that is both practical and efficient.

Example Systems

As shown in FIG. 1, a vehicle 100 in accordance with one aspect of thedisclosure includes various components. While certain aspects of thedisclosure are particularly useful in connection with specific types ofvehicles, the vehicle may be any type of vehicle including, but notlimited to, cars, trucks, motorcycles, buses, recreational vehicles,etc. The vehicle may have one or more computing devices, such ascomputing device 110 containing one or more processors 120, memory 130and other components typically present in general purpose computingdevices.

The memory 130 stores information accessible by the one or moreprocessors 120, including instructions 134 and data 132 that may beexecuted or otherwise used by the processor 120. The memory 130 may beof any type capable of storing information accessible by the processor,including a computing device-readable medium, or other medium thatstores data that may be read with the aid of an electronic device, suchas a hard-drive, memory card, ROM, RAM, DVD or other optical disks, aswell as other write-capable and read-only memories. Systems and methodsmay include different combinations of the foregoing, whereby differentportions of the instructions and data are stored on different types ofmedia.

The instructions 134 may be any set of instructions to be executeddirectly (such as machine code) or indirectly (such as scripts) by theprocessor. For example, the instructions may be stored as computingdevice code on the computing device-readable medium. In that regard, theterms “instructions” and “programs” may be used interchangeably herein.The instructions may be stored in object code format for directprocessing by the processor, or in any other computing device languageincluding scripts or collections of independent source code modules thatare interpreted on demand or compiled in advance. Functions, methods androutines of the instructions are explained in more detail below.

The data 132 may be retrieved, stored or modified by processor 120 inaccordance with the instructions 134. For instance, although the claimedsubject matter is not limited by any particular data structure, the datamay be stored in computing device registers, in a relational database asa table having a plurality of different fields and records, XMLdocuments or flat files. The data may also be formatted in any computingdevice-readable format.

The one or more processor 120 may be any conventional processors, suchas commercially available CPUs or GPUs. Alternatively, the one or moreprocessors may be a dedicated device such as an ASIC or otherhardware-based processor. Although FIG. 1 functionally illustrates theprocessor, memory, and other elements of computing device 110 as beingwithin the same block, it will be understood by those of ordinary skillin the art that the processor, computing device, or memory may actuallyinclude multiple processors, computing devices, or memories that may ormay not be stored within the same physical housing. For example, memorymay be a hard drive or other storage media located in a housingdifferent from that of computing device 110. Accordingly, references toa processor or computing device will be understood to include referencesto a collection of processors or computing devices or memories that mayor may not operate in parallel.

Computing devices 110 may include all of the components normally used inconnection with a computing device such as the processor and memorydescribed above as well as a user input 150 (e.g., a mouse, keyboard,touch screen and/or microphone), various electronic displays (e.g., amonitor having a screen or any other electrical device that is operableto display information), and speakers to provide information to apassenger of the vehicle 100 as needed. For example, electronic display152 may be located within a cabin of vehicle 100 and may be used bycomputing devices 110 to provide information to passengers within thevehicle 100. Electronic display 154 may be located on an exterior of thevehicle, such as mounted on the roof or at some other portion of thevehicle. Alternatively, the display 154 or in an interior location whichallows persons outside of the vehicle to view information presented onthe display 154, such as s a display mounted at the center of adashboard of the vehicle and oriented outwards. In some instances, thedisplays 152, 154, may be flat, curved, and may extend 360 degrees. Asdiscussed in further detail below, the computing devices 110 incombination with display 152 and/or display 154 may be a notificationsystem which can provide information to passengers as well as otherpersons outside of the vehicle 100.

Computing devices 110 may also include one or more wireless networkconnections 156 to facilitate communication with other computingdevices, such as the client computing devices and server computingdevices described in detail below. The wireless network connections mayinclude short range communication protocols such as Bluetooth, Bluetoothlow energy (LE), cellular connections, as well as various configurationsand protocols including the Internet, World Wide Web, intranets, virtualprivate networks, wide area networks, local networks, private networksusing communication protocols proprietary to one or more companies,Ethernet, WiFi and HTTP, and various combinations of the foregoing.

The computing devices 110 may function as an autonomous control system,and may be capable of communicating with various components of thevehicle in order to control the vehicle in an autonomous driving mode.For example, returning to FIG. 1, the computing devices 110 may be incommunication with various systems of vehicle 100, such as decelerationsystem 160, acceleration system 162, steering system 164, routing system166, planning system 168, routing system 170, positioning system 172,and perception system 174 in order to control the movement, speed, etc.of vehicle 100 in accordance with the instructions 134 of memory 130 inthe autonomous driving mode.

As an example, a computing device of the computing devices 110 mayinteract with deceleration system 160 and acceleration system 162 inorder to control the speed of the vehicle. Similarly, steering system164 may be used by computing devices 110 in order to control thedirection of vehicle 100. For example, if vehicle 100 is configured foruse on a road, such as a car or truck, the steering system may includecomponents to control the angle of wheels to turn the vehicle. Thecomputing devices 110 may also use the signaling system in order tosignal the vehicle's intent to other drivers or vehicles, for example,by lighting turn signals or brake lights when needed.

Routing system 166 may be used by the computing devices 110 in order togenerate a route to a destination. Planning system 168 may be used bycomputing device 110 in order to follow the route. In this regard, theplanning system 168 and/or routing system 166 may store detailed mapinformation, e.g., highly detailed maps identifying a road networkincluding the shape and elevation of roadways, lane lines,intersections, crosswalks, speed limits, traffic signals, buildings,signs, real time traffic information, pullover spots, vegetation, orother such objects and information.

FIG. 2 is an example of map information 200 for a small section ofroadway including intersections 202, 203, 204, 205, 206. FIG. 2A depictsa portion of the map information 200 that includes informationidentifying the shape, location, and other characteristics of lanemarkers or lane lines 210, 212, 214, 216, 218, lanes 220, 221, 222, 223,224, 225, 226, 227, 228, traffic control devices including trafficsignal lights 230, 232, 234 and stop sign 236 (not depicted in FIG. 2Bfor clarity), stop lines 240, 242, 244, as well as a non-drivable area280. In this example, lane 221 approaching intersection 204 is a leftturn only lane, lane 222 approaching intersection 206 is a left turnonly lane, and lane 226 is a one-way street where the direction oftraffic moves away from intersection 204. In addition to theaforementioned features, the map information may also includeinformation that identifies the direction of traffic for each lane aswell as information that allows the computing devices 110 to determinewhether the vehicle has the right of way to complete a particularmaneuver (i.e. complete a turn or cross a lane of traffic orintersection).

Although the map information is depicted herein as an image-based map,the map information need not be entirely image based (for example,raster). For instance, the map information may include one or moreroadgraphs, graph networks or road networks of information such asroads, lanes, intersections, and the connections between these featureswhich may be represented by road segments. Each feature in the map mayalso be stored as graph data and may be associated with information suchas a geographic location and whether or not it is linked to otherrelated features, for example, a stop sign may be linked to a road andan intersection, etc. In some examples, the associated data may includegrid-based indices of a road network to allow for efficient lookup ofcertain road network features.

In this regard, in addition to the aforementioned physical featureinformation, the map information may include a plurality of graph nodesand edges representing road or lane segments that together make up theroad network of the map information. Each edge is defined by a startinggraph node having a specific geographic location (e.g. latitude,longitude, altitude, etc.), an ending graph node having a specificgeographic location (e.g. latitude, longitude, altitude, etc.), and adirection. This direction may refer to a direction the vehicle 100 mustbe moving in in order to follow the edge (i.e. a direction of trafficflow). The graph nodes may be located at fixed or variable distances.For instance, the spacing of the graph nodes may range from a fewcentimeters to a few meters and may correspond to the speed limit of aroad on which the graph node is located. In this regard, greater speedsmay correspond to greater distances between graph nodes.

The routing system 166 may use the roadgraph to determine a route from acurrent location (e.g. a location of a current node) to a destination.Routes may be generated using a cost-based analysis which attempts toselect a route to the destination with the lowest cost. Costs may beassessed in any number of ways such as time to the destination, distancetraveled (each edge may be associated with a cost to traverse thatedge), types of maneuvers required, convenience to passengers or thevehicle, etc. Each route may include a list of a plurality of nodes andedges which the vehicle can use to reach the destination. Routes may berecomputed periodically as the vehicle travels to the destination.

Positioning system 172 may be used by computing devices 110 in order todetermine the vehicle's relative or absolute position on a map or on theearth. For example, the positioning system 172 may include a GPSreceiver to determine the device's latitude, longitude and/or altitudeposition. Other location systems such as laser-based localizationsystems, inertial-aided GPS, or camera-based localization may also beused to identify the location of the vehicle. The location of thevehicle may include an absolute geographical location, such as latitude,longitude, and altitude, a location of a node or edge of the roadgraphas well as relative location information, such as location relative toother cars immediately around it which can often be determined with lessnoise that absolute geographical location.

The positioning system 170 may also include other devices incommunication with the computing devices computing devices 110, such asan accelerometer, gyroscope or another direction/speed detection deviceto determine the direction and speed of the vehicle or changes thereto.By way of example only, an acceleration device may determine its pitch,yaw or roll (or changes thereto) relative to the direction of gravity ora plane perpendicular thereto. The device may also track increases ordecreases in speed and the direction of such changes. The device'sprovision of location and orientation data as set forth herein may beprovided automatically to the computing device 110, other computingdevices and combinations of the foregoing.

The perception system 174 also includes one or more components fordetecting objects external to the vehicle such as other vehicles,obstacles in the roadway, traffic signals, signs, trees, etc. Forexample, the perception system 174 may include lasers, sonar, radar,cameras and/or any other detection devices that record data which may beprocessed by the computing devices of the computing devices 110. In thecase where the vehicle is a passenger vehicle such as a minivan, theminivan may include a laser or other sensors mounted on the roof orother convenient location. For instance, FIG. 3 is an example externalview of vehicle 100. In this example, roof-top housing 310 and domehousing 312 may include a LIDAR sensor as well as various cameras andradar units. In addition, housing 320 located at the front end ofvehicle 100 and housings 330, 332 on the driver's and passenger's sidesof the vehicle may each store a LIDAR sensor. For example, housing 330is located in front of driver door 360. Vehicle 100 also includeshousings 340, 342 for radar units and/or cameras also located on theroof of vehicle 100. Additional radar units and cameras (not shown) maybe located at the front and rear ends of vehicle 100 and/or on otherpositions along the roof or roof-top housing 310.

The computing devices 110 may be capable of communicating with variouscomponents of the vehicle in order to control the movement of vehicle100 according to primary vehicle control code of memory of the computingdevices 110. For example, returning to FIG. 1, the computing devices 110may include various computing devices in communication with varioussystems of vehicle 100, such as deceleration system 160, accelerationsystem 162, steering system 164, routing system 166, planning system168, positioning system 170, perception system 174, and power system 178(i.e. the vehicle's engine or motor) in order to control the movement,speed, etc. of vehicle 100 in accordance with the instructions 134 ofmemory 130.

The various systems of the vehicle may function using autonomous vehiclecontrol software in order to determine how to and to control thevehicle. As an example, a perception system software module of theperception system 174 may use sensor data generated by one or moresensors of an autonomous vehicle, such as cameras, LIDAR sensors, radarunits, sonar units, etc., to detect and identify objects and theircharacteristics. These characteristics may include location, type,heading, orientation, speed, acceleration, change in acceleration, size,shape, etc. In some instances, characteristics may be input into abehavior prediction system software module of a behavior modeling system176 which uses various behavior models based on object type to output apredicted future behavior for a detected object. In other instances, thecharacteristics may be put into one or more detection system softwaremodules, such as a traffic light detection system software moduleconfigured to detect the states of known traffic signals, constructionzone detection system software module configured to detect constructionzones from sensor data generated by the one or more sensors of thevehicle as well as an emergency vehicle detection system configured todetect emergency vehicles from sensor data generated by sensors of thevehicle. Each of these detection system software modules may usesvarious models to output a likelihood of a construction zone or anobject being an emergency vehicle. Detected objects, predicted futurebehaviors, various likelihoods from detection system software modules,the map information identifying the vehicle's environment, positioninformation from the positioning system 170 identifying the location andorientation of the vehicle, a destination location or node for thevehicle as well as feedback from various other systems of the vehiclemay be input into a planning system software module of the planningsystem 168. The planning system 168 may use this input to generatetrajectories for the vehicle to follow for some brief period of timeinto the future based on a route generated by a routing module of therouting system 166. In this regard, the trajectories may define thespecific characteristics of acceleration, deceleration, speed, etc. toallow the vehicle to follow the route towards reaching a destination. Acontrol system software module of the computing devices 110 may beconfigured to control movement of the vehicle, for instance bycontrolling braking, acceleration and steering of the vehicle, in orderto follow a trajectory.

The computing devices 110 may control the vehicle in an autonomousdriving mode by controlling various components. For instance, by way ofexample, the computing devices 110 may navigate the vehicle to adestination location completely autonomously using data from thedetailed map information and planning system 168. The computing devices110 may use the positioning system 170 to determine the vehicle'slocation and perception system 174 to detect and respond to objects whenneeded to reach the location safely. Again, in order to do so, computingdevice 110 and/or planning system 168 may generate trajectories andcause the vehicle to follow these trajectories, for instance, by causingthe vehicle to accelerate (e.g., by supplying fuel or other energy tothe engine or power system 178 by acceleration system 162), decelerate(e.g., by decreasing the fuel supplied to the engine or power system178, changing gears, and/or by applying brakes by deceleration system160), change direction (e.g., by turning the front or rear wheels ofvehicle 100 by steering system 164), and signal such changes (e.g., bylighting turn signals). Thus, the acceleration system 162 anddeceleration system 160 may be a part of a drivetrain that includesvarious components between an engine of the vehicle and the wheels ofthe vehicle. Again, by controlling these systems, computing devices 110may also control the drivetrain of the vehicle in order to maneuver thevehicle autonomously.

Computing device 110 of vehicle 100 may also receive or transferinformation to and from other computing devices, such as those computingdevices that are a part of the transportation service as well as othercomputing devices. FIGS. 4 and 5 are pictorial and functional diagrams,respectively, of an example system 400 that includes a plurality ofcomputing devices 410, 420, 430, 440 and a storage system 450 connectedvia a network 460. System 400 also includes vehicle 100 and vehicle100A, which may be configured the same as or similarly to vehicle 100.Although only a few vehicles and computing devices are depicted forsimplicity, a typical system may include significantly more.

As shown in FIG. 5, each of computing devices 410, 420, 430, 440 mayinclude one or more processors, memory, data and instructions. Suchprocessors, memories, data and instructions may be configured similarlyto one or more processors 120, memory 130, data 132, and instructions134 of computing device 110.

The network 460, and intervening graph nodes, may include variousconfigurations and protocols including short range communicationprotocols such as Bluetooth, Bluetooth LE, the Internet, World Wide Web,intranets, virtual private networks, wide area networks, local networks,private networks using communication protocols proprietary to one ormore companies, Ethernet, WiFi and HTTP, and various combinations of theforegoing. Such communication may be facilitated by any device capableof transmitting data to and from other computing devices, such as modemsand wireless interfaces.

In one example, one or more computing devices 410 may include one ormore server computing devices having a plurality of computing devices,e.g., a load balanced server farm, that exchange information withdifferent nodes of a network for the purpose of receiving, processingand transmitting the data to and from other computing devices. Forinstance, one or more computing devices 410 may include one or moreserver computing devices that are capable of communicating withcomputing device 110 of vehicle 100 or a similar computing device ofvehicle 100A as well as computing devices 420, 430, 440 via the network460. For example, vehicles 100, 100A, may be a part of a fleet ofvehicles that can be dispatched by server computing devices to variouslocations. In this regard, the server computing devices 410 may functionas a dispatching server computing system which can be used to dispatchvehicles such as vehicle 100 and vehicle 100A to different locations inorder to pick up and drop off passengers. In addition, server computingdevices 410 may use network 460 to transmit and present information to auser, such as user 422, 432, 442 on a display, such as displays 424,434, 444 of computing devices 420, 430, 440. In this regard, computingdevices 420, 430, 440 may be considered client computing devices.

As shown in FIG. 5, each client computing device 420, 430, 440 may be apersonal computing device intended for use by a user 422, 432, 442, andhave all of the components normally used in connection with a personalcomputing device including a one or more processors (e.g., a centralprocessing unit (CPU)), memory (e.g., RAM and internal hard drives)storing data and instructions, a display such as displays 424, 434, 444(e.g., a monitor having a screen, a touch-screen, a projector, atelevision, or other device that is operable to display information),and user input devices 426, 436, 446 (e.g., a mouse, keyboard,touchscreen or microphone). The client computing devices may alsoinclude a camera for recording video streams, speakers, a networkinterface device, and all of the components used for connecting theseelements to one another.

Although the client computing devices 420, 430, and 440 may eachcomprise a full-sized personal computing device, they may alternativelycomprise mobile computing devices capable of wirelessly exchanging datawith a server over a network such as the Internet. By way of exampleonly, client computing device 420 may be a mobile phone or a device suchas a wireless-enabled PDA, a tablet PC, a wearable computing device orsystem, or a netbook that is capable of obtaining information via theInternet or other networks. In another example, client computing device430 may be a wearable computing system, shown as a wristwatch as shownin FIG. 4. As an example the user may input information using a smallkeyboard, a keypad, microphone, using visual signals with a camera, or atouch screen.

In some examples, client computing device 420 may be a mobile phone usedby a passenger of a vehicle. In other words, user 422 may represent apassenger. In addition, client communication device 430 may represent asmart watch for a passenger of a vehicle. In other words, user 432 mayrepresent a passenger. The client communication device 440 may representa workstation for an operations person, for example, a remote assistanceoperator or someone who may provide remote assistance to a vehicleand/or a passenger. In other words, user 442 may represent a remoteassistance operator. Although only a few passengers and operationspersons are shown in FIGS. 4 and 5, any number of such passengers andremote assistance operators (as well as their respective clientcomputing devices) may be included in a typical system.

As with memory 130, storage system 450 can be of any type ofcomputerized storage capable of storing information accessible by theserver computing devices 410, such as a hard-drive, memory card, ROM,RAM, DVD, CD-ROM, write-capable, and read-only memories. In addition,storage system 450 may include a distributed storage system where datais stored on a plurality of different storage devices which may bephysically located at the same or different geographic locations.Storage system 450 may be connected to the computing devices via thenetwork 460 as shown in FIGS. 4 and 5, and/or may be directly connectedto or incorporated into any of the computing devices 110, 410, 420, 430,440, etc.

Example Methods

In addition to the operations described above and illustrated in thefigures, various operations will now be described. It should beunderstood that the following operations do not have to be performed inthe precise order described below. Rather, various steps can be handledin a different order or simultaneously, and steps may also be added oromitted.

In one aspect, a user may download an application for requesting avehicle to a client computing device. For example, users 122 and 132 maydownload the application via a link in an email, directly from awebsite, or an application store to client computing devices 120 and130. For example, client computing device may transmit a request for theapplication over the network, for example, to one or more servercomputing devices 110, and in response, receive the application. Theapplication may be installed locally at the client computing device.

The user may then use his or her client computing device to access theapplication and request a vehicle. As an example, a user such as user432 may use client computing device 430 to send a request to one or moreserver computing devices 110 for a vehicle. As part of this, the usermay identify a pickup location, a destination location, a pickuplocation and a drop off location. In this regard, the drop off locationmay be a physically different location from a destination location.

A user or passenger may specify a pick up, intermediate destination, andfinal destination locations in various ways. As an example, a pickuplocation can be defaulted to the current location of the passenger'sclient computing device, but may also be a recent or saved location nearthe current location associated with the passenger's account. Thepassenger may enter an address or other location information, tap alocation on a map or select a location from a list in order to identifya pickup and/or destination location. For instance, the client computingdevice 120 may send its current location, such as a GPS location, to theone or more server computing devices 110 via network 460 and/or adestination name or address for any intermediate and the finaldestination. In response, the server computing devices 410 may provideone or more suggested locations or may identify the current location asa pickup location and locations corresponding to the destination name oraddress as an intermediate or final destination for the vehicle. One theuser (now a passenger) has selected or confirmed the pickup anddestination locations, the server computing devices may assign avehicle, such as vehicle 100, to the passenger and the passenger's tripand send dispatching instructions to the vehicle including the pickuplocation, an intermediate destination, and the final destination. Thismay cause the vehicle to control itself in the autonomous driving modetowards the pickup location, for instance by using the various systemsof the vehicle as described above, in order to complete the trip.Although the examples herein relate to transporting passengers, similarfeatures may be used for the transportation of goods or cargo.

As noted above, the features described herein may enable an autonomousvehicle, such as vehicle 100, to communicate with persons outside of thevehicle, including an assigned passenger. To do so, information may bepresented on the display 152, 154. In addition, information provided onthe display can be contextually-aware of the vehicle's environment. Forinstance, the vehicle's various systems may provide a notificationsystem with information based on time of day, weather, level of trafficcongestion, location of objects, as well as other social and situationalinformation about the vehicle's environment. The notification system maythen dynamically adjust the information accordingly. This may eveninvolve adjusting information appropriately to increase legibility andcomprehension of a message. Such adjustments may include, for example,amplifying or minimizing size, color, brightness, hue, or timing ofcontent shown on the display based on the context in which the vehicleis driving and/or the intended viewer. Those adjustments might also useinformation about the passenger such as any preferences (maybe indicatedby a passenger or as a default via an application of the passenger'sclient computing device) for larger fonts.

For instance, the context and content of information displayed on thedisplay may be determined based on a distance (in time and/or space) toa pickup location for a passenger or a distance to a passenger of thevehicle as well as related considerations. FIG. 8 provides an exampleflow diagram 800 for displaying notification on a display of anautonomous vehicle which may be performed by one or more processors ofone or more computing devices such as the processors 120 of computingdevices 110. At block 810, when the vehicle is between a first distanceand a second distance of a location, the location being a destinationfor the vehicle or a location of a passenger is determined. At block820, when the vehicle is determined to be between the first distance andthe second distance of the location, a first notification is displayedon a display of the vehicle. The second is less than the first distance.

For instance, a passenger's location may be determined from one or moreof a location approximated from a communication link between thepassenger's client computing device (e.g. mobile phone) and thecomputing devices 110 or other computing devices of the vehicle, forinstance via near field communication, Bluetooth, or other communicationprotocols. In addition or alternatively, the computing devices 110 mayreceive a location, e.g. a location identified by the passenger as apickup location and/or determined from one or more of WiFi or GPSsignals at the client computing devices, via the aforementionedcommunication link or from one or more server computing devices, such asthe server computing devices 410, which may act as an intermediarybetween the passenger and the vehicle. In addition, the perceptionsystem 178 and/or the computing devices 110 (using information publishedby the perception system) may attempt to identify pedestrians who may bethe passenger who are actively making progress towards the vehicle (e.g.walking towards rather than away from).

As noted above, the computing devices 110 may determine whether thevehicle 100 is between a first distance to the destination and a seconddistance to the destination or the passenger. The distance to thedestination or the passenger may be a “straight line” distance or may bea distance along a route that the vehicle is currently traveling. Inaddition, the first and second distances may be defined in space (e.g.meters or feet) or in time (e.g. seconds).

FIG. 6A provides an example representation of vehicle 100 approaching alocation 610 which may be a destination of the vehicle (e.g. to pick upa passenger) or a location of a passenger assigned to the vehicle. Afirst distance from the location 610 is identified by marker 620, and asecond distance from the location 610 is identified by marker 630. Inthis example, vehicle 100 is depicted an arbitrary distance from marker620. As noted above, the distances D1, D2 may be measured in time or inspace. In addition, the distances may be a straight-line (e.g. “as thecrow flies”) distance or may be a distance along a route that thevehicle is currently traveling to reach the location 610.

FIG. 7 provides a bird's eye view of the vehicle 100 driving in ageographic area 700 corresponding to the area of the map information200. In this regard, intersections 202, 203, 204, 205, 206 correspond tointersections 702, 703, 704, 705, 706, lane lines 210, 212, 214, 216,218 correspond to lane lines 710, 712, 714, 716, 718, lanes 220, 221,222, 223, 224, 225, 226, 227, 228 correspond to lanes 720, 721, 722,723, 724, 725, 726, 727, 728, traffic signal lights 230, 232, 234correspond to traffic signal lights 730, 732, 734, stop sign 236corresponds to stop sign 736, stop lines 240, 242, 244 correspond tostop lines 740, 742, 744, and non-drivable area 280 corresponds tonon-drivable area 780.

As shown in FIG. 7 vehicle 100 is following a route 792 to a location790 in order to pick up an assigned passenger. In this example, thelocation 790 may represent a destination of the vehicle, oralternatively, a location of a passenger assigned to the vehicle. Inthis example, the distance D3 between the vehicle and the location 790along the route 792 is longer than a straight-line distance D4 betweenthe vehicle and the location 790.

For example, when the vehicle is the distance D1 or between the twodistances D1 and D2 to the destination or the passenger, the vehicle maydisplay a first notification on the display. This first notification maybe fairly simple, such as a single block of color. For example, turningto FIG. 6B, a first notification 650 may be displayed on the display152, 154 by the computing devices 110 when the vehicle reaches thelocation of marker 620 (or rather is the distance D1 from the location610) or is between the locations of marker 620 and 630 (or ratherbetween the two distances D1 and D2 from the location 610). In thisexample, the first notification 650 includes only a “color” (representedby shading). In this regard, the first notification does not includeadditional information such as text (including alphanumeric characters)and/or one or more images, icons, emoticons, emojis or other details.This may be because the first and second distance are far enough awayfrom the destination or the passenger that the passenger would have ahard time perceiving any additional detail, such as 30 to 100 meters, 10seconds to 30 seconds, or more or less. In this regard, the greater thefirst or second distances are, the greater amount of time or longer thenotifications may be displayed.

Returning to FIG. 8, at block 830, when the vehicle is within the seconddistance from the location is determined. At block 840, when the vehicleis determined to be within the second distance from the location, asecond notification is displayed on the display. The second notificationprovides additional information not provided by the first notification.For instance, the vehicle's computing devices may determine whether thedistance to the destination or the passenger is at or less than thesecond distance. At distances at or less than the second distance, thecomputing devices 110 may display a second notification on the display152, 154. This second notification may include the color of the firstnotification, but may also provide additional information such as text(including alphanumeric characters) and/or one or more images, icons,emoticons, emojis or other details which the passenger can use toidentify whether the vehicle has been assigned to the passenger. Forinstance, images, icons, emoticons, emojis or other details may bedisplayed with text in order to distinguish between vehicle's assignedto different passengers. For example, an icon may be used to make commoninitials less ambiguous, such as placing an icon before or after “JS”for John Smith. Such images, icons, emoticons, emojis or other detailsmay be selected by a passenger when setting up a trip, etc.

For example, turning to FIG. 6C, a second notification 660 may bedisplayed when the vehicle reaches the location of marker 630 (or ratheris the distance D2 from the location 610) or is between the locations ofmarker 630 and the location 610 (or rather less than the distance D2 ofmarker 630 from the location 610). In this example, the secondnotification 660 displayed on the display 152, 154 includes both the“color” (represented by shading) from the first notification 650 as wellas text, here, “Joe's Car” identifying the vehicle 100 as being assignedto passenger “Joe”. In this regard, the second notification 660 providesadditional information not provided by the first notification 650.

The first and second distances may be fixed values (e.g. predetermined)or may be default values that may be adjusted by the computing devices110 based on the context in which the vehicle is currently driving. Forinstance, the first and/or second distances may be increased ordecreased depending on the speed of the vehicle, the number of otherpedestrians or passengers waiting for a pickup nearby to the destinationof the vehicle and/or the passenger, and/or the number of othervehicles. These other vehicles may or may not be a part of the fleet ofautonomous vehicles attempting to pick up or drop off passengers.

Information about the context in which the vehicle is driving may bedetermined, for instance, by information received by the computingdevices 110 from remote computing devices (such as the server computingdevices 410), the perception system 174, and/or may be determined fromthe map information. For example, information about weather or trafficconditions may be received from the server computing devices or anotherremote computing device. Information about other detected vehicles andpedestrians, and weather conditions may be received from the perceptionsystem 174 or other processing and detection systems of the vehicle(such as those dedicated to detecting weather conditions, etc.).Information about speed limits and other road conditions (e.g. geometry)may be determined from the map information.

When determining the first and second distances, the computing devices110 may take into consideration the speed of the vehicle 100. The speedof the vehicle 100 may be determined, for example, using feedback fromthe vehicle's odometer and/or mathematically based on the vehicle'schange in location determined using feedback from the positioning system172. For instance, at higher speeds, even when the vehicle is betweenthe first and second distances, it may be less useful to providedisplayed information. In this regard, different first and/or seconddistances may be used when the vehicle pickup within or near a schoolzone, a construction zone, a residential area, on a 35 mph or higherstreet, etc. as determined from annotations, flags or other devices inthe map information. Since speed is directly tied to time and distancetraveled, the first and second distances may be adjusted based on thespeed zone and/or the speed the vehicle is traveling. For example, thiswill mean that when a vehicle is picking up riders in a school zone, thefirst and/or second distances may be decreased, since the vehicle istraveling at a slower speed. In another example, the distances might becomputed dynamically using a logarithmic or other formula based oncurrent speed and/or distance. For instance, if the vehicle is turninginto a parking spot to pick up a passenger in a parking lot from ahigher speed roadway, as the vehicle's speed may be higher as itapproaches the parking spot, the first and second distances can beadjusted to account for displaying information on a 45 mph road (in thiscase increase the first and/or second distances).

For example, a passenger may require more time to see the notificationsin heavier traffic conditions, when there are many people waiting to bepicked up, or when there are multiple autonomous vehicles picking up ordropping off passengers and thus, the first and/or second distances maybe increased. Similarly, in congested areas where there might be a lotof competing visual factors (traffic, environmental surroundings, etc.),the first and/or second distances may be increased. In this regard, thefirst and second distances may be increased thereby increasing theamount of time that the first and/or second notifications are displayed.This, in turn, may provide more time for passengers to identify andrecognize their assigned vehicle. In such circumstances, the display mayalso increase saturation or hue to aid in identification andrecognition.

In another example, in a low-traffic suburban area at night, with slowerspeed limits, by the computing devices 110 may begin displaying thefirst notification closer to the destination rather than farther away,as the time needed for identification and recognition may be reduced insuch circumstances. In this regard, the first and second distances maybe decreased. In contrast, in daytime, the time needed foridentification and recognition may be longer if the ambient light isbright. In this regard, the first and second distances may be increased.

In addition, the proximity to multiple pedestrians and/or pedestriansother than the passenger, may be used by the computing devices 110 todecrease the second distance. For example, in a construction zone withpeople who can be in fairly close proximity to the vehicle, the seconddistance may be increased in order to adjust timing of when text mightappear so as to appear at a reasonable distance from such pedestrians,given the speed the vehicle is travelling.

In addition, the brightness of the first or second notification may bedetermined by the computing devices 110 based on circumstances such ascurrent ambient lighting conditions, current weather conditions, currenttraffic conditions (i.e. brighter in heavier traffic), or simply bebrighter the farther the vehicle is from the destination or thepassenger. For example, in foggy or overcast conditions, brightness maybe adjusted downwards. In another example, lighted and shaded areas mayrequire different levels of brightness to retain contrast for legibilityto allow a passenger to identify and recognize their assigned vehicle.For example, in the evening, the display may be clear and legible at alower lumen level; however when picking up in a lighted parking area,underneath a street lamp or other well-lit area, the display may need toincrease in brightness to increase contrast. In this regard, the firstnotification may be displayed brighter than the second notification orthe second notification may be displayed brighter than the firstnotification depending upon the circumstances.

The computing devices 110 may implement the different first and seconddistances using lookup tables or other data structures prestored in thememory 130 or elsewhere on the vehicle based on the context in which thevehicle is driving and the destination (e.g. what type of locations areat or near where a passenger is going to be picked up. For example,TABLE 1 provides information for displaying a first notification when avehicle is approaching a pickup of a passenger at or near (e.g. withinsome predetermined distance) of an intersection in a residential area or25 mile per hour zone (as determined from the map information). In thisexample, the values provided in TABLE 1 may be adjusted based onlighting conditions. For example, during the evening or night timehours, when the ambient lighting is determined to be or is expected tobe lower, the distances may be increased 25 meters.

Turning to TABLE 1 below, if there is no traffic, the first notificationmay be displayed when the vehicle is within 100 meters of thedestination of the vehicle or the passenger when there is only a singlepedestrian detected as this person is likely to be the passengerassigned to the vehicle. If there is high vehicular traffic or the areaaround the destination or the passenger is otherwise congested, thefirst notification may be displayed when the vehicle is 175 meters fromthe destination of the vehicle or the passenger.

TABLE 1 also provides information for how the first notification shouldbe displayed when there are multiple riders or groups of riders waitingfor a pickup at the destination. In this example, the first distancesare increased. In this example, if there is no vehicular traffic, thefirst notification may be displayed when the vehicle is within 175meters of the destination of the vehicle or the passenger. If there ishigh vehicle traffic or the area around the destination or the passengeris otherwise congested, the first notification may be displayed when thevehicle is 200 meters from the destination of the vehicle or thepassenger.

TABLE 1 Approaching a pickup near or at intersection in residential area(25 mph Single person/group Multiple riders/groups of zone) (rider)riders No traffic Start display 100 m* before Start display 175 m*before High traffic, congested Start display 175 m* before Start display200 m* before *increase 25 m depending on lighting conditions

For example, TABLE 2 below provides information for displaying a firstnotification when a vehicle is approaching a pickup of a passenger at ornear a large parking area from (10 mph road) in a mall or shoppingcenter or 10 mile per hour zone (as determined from the mapinformation). In this example, the values provided in TABLE 2 may beadjusted based on lighting conditions. For example, during the eveningor night time hours, when the ambient lighting is determined to be or isexpected to be lower, the distances may be increased 50 meters or moreor less. As shown in TABLE 2, if there is no traffic, the firstnotification may be displayed when the vehicle is within 50 meters ofthe destination of the vehicle or the passenger when there is only asingle pedestrian detected as this person is likely to be the passengerassigned to the vehicle. If there is high vehicular traffic or the areaaround the destination or the passenger is otherwise congested, thefirst notification may be displayed when the vehicle is 100 meters fromthe destination of the vehicle or the passenger.

TABLE 2 also provides information for how the first notification shouldbe displayed when there are multiple riders or groups of riders waitingfor a pickup at the destination. In this example, the first distancesare increased. In this example, if there is no vehicular traffic, thefirst notification may be displayed when the vehicle is within 75 metersof the destination of the vehicle or the passenger. If there is highvehicle traffic or the area around the destination or the passenger isotherwise congested, the first notification may be displayed when thevehicle is 150 meters from the destination of the vehicle or thepassenger.

TABLE 2 Approaching a pickup in large parking area from (10 mph road) inmall/shopping Single person Group/cluster center (rider) of people Notraffic Start display 50 m 

 before Start display 75 m 

 before High traffic, congested Start display 100 m 

 before Start display 150 m 

 before

 increase 50 m depending on lighting conditions

Although TABLES 1 and 2 above provide examples of different distances inspace, similar distances could also be determined in time. In addition,Tables 1 and 2 provide example distances for the first distance, butsuch tables or other tables may also include second distances forsimilar conditions as provided in the examples of Tables 3 and 4 below.

TABLE 3 provides information for displaying a second notification when avehicle is approaching a pickup of a passenger at or near anintersection in a residential area or 25 mile per hour zone (asdetermined from the map information). In this example, the valuesprovided in TABLE 3 may be adjusted based on lighting conditions. Forexample, during the evening or night time hours, when the ambientlighting is determined to be or is expected to be lower, the distancesmay be increased 25 meters.

Turning to TABLE 3, if there is no traffic, the second notification maybe displayed when the vehicle is within 50 meters of the destination ofthe vehicle or the passenger when there is only a single pedestriandetected as this person is likely to be the passenger assigned to thevehicle. If there is high vehicular traffic or the area around thedestination or the passenger is otherwise congested, the secondnotification may be displayed when the vehicle is 88 meters from thedestination of the vehicle or the passenger.

TABLE 3 also provides information for how the second notification shouldbe displayed when there are multiple riders or groups of riders waitingfor a pickup at the destination. In this example, the second distancesare increased. In this example, if there is no vehicular traffic, thesecond notification may be displayed when the vehicle is within 88meters of the destination of the vehicle or the passenger. If there ishigh vehicle traffic or the area around the destination or the passengeris otherwise congested, the second notification may be displayed whenthe vehicle is 100 meters from the destination of the vehicle or thepassenger.

TABLE 3 Approaching a pickup near or at intersection in residential area(25 mph Single person/group Multiple riders/groups of zone) (rider)riders No traffic Start display 50 m* before Start display 88 m* beforeHigh traffic, congested Start display 188 m 

 before Start display 100 m 

 before *increase 25 m depending on lighting conditions

For example, TABLE 4 below provides information for displaying a secondnotification when a vehicle is approaching a pickup of a passenger at ornear a large parking area from (10 mph road) in a mall or shoppingcenter or 10 mile per hour zone (as determined from the mapinformation). In this example, the values provided in TABLE 5 may beadjusted based on lighting conditions. For example, during the eveningor night time hours, when the ambient lighting is determined to be or isexpected to be lower, the distances may be increased 50 meters or moreor less.

Turning to TABLE 4, if there is no traffic, the second notification maybe displayed when the vehicle is within 25 meters of the destination ofthe vehicle or the passenger when there is only a single pedestriandetected as this person is likely to be the passenger assigned to thevehicle. If there is high vehicular traffic or the area around thedestination or the passenger is otherwise congested, the secondnotification may be displayed when the vehicle is 50 meters from thedestination of the vehicle or the passenger.

TABLE 4 also provides information for how the second notification shouldbe displayed when there are multiple riders or groups of riders waitingfor a pickup at the destination. In this example, the second distancesare increased. In this example, if there is no vehicular traffic, thesecond notification may be displayed when the vehicle is within 48meters of the destination of the vehicle or the passenger. If there ishigh vehicle traffic or the area around the destination or the passengeris otherwise congested, the second notification may be displayed whenthe vehicle is 75 meters from the destination of the vehicle or thepassenger.

TABLE 4 Approaching a pickup in large parking area from (10 mph road) inmall/shopping Single person Group/cluster center (rider) of people Notraffic Start display 25 m 

 before Start display 48 m 

 before High traffic, congested Start display 50 m 

 before Start display 75 m 

 before

 increase 50 m depending on lighting conditions

In addition, in some instances, a plurality of autonomous vehicles maycoordinate and adjust display attributes such as hue and brightness,depending on the status of each passenger and that passenger'srespective assigned vehicles. For example, if vehicle-A, B, & C arewaiting on their riders-A, B, & C; if rider-A is outside of a visiblerange, rider-B is fairly close by, and rider-C is waiting, vehicle-Cmight have the brightest and most saturated hue, while and vehicle-B maydisplay at a lower visual prominence to remain visible but giveprecedence to vehicle-C.

In certain cases where there is more than one display or where thedisplay 152, 154 is able to display different information in differentdirections (e.g. a 360 degree display), the location of the passengermay be used to select a display or display the notifications on thedisplay in such a way that the passenger would have a line of sight tothe displayed notifications. In this way, the notification may bedirectional or oriented towards the passenger. In addition, in the caseof multi-directional displays the notifications may “follow” thelocation of the passenger. This approach may also be used when providingnotifications to non-passengers, such as in the examples of expressingintent below.

The display may also be changed based upon a pedestrian's gaze orbehavior. For example, a pedestrian may be identified as a passengerassigned to a vehicle based on the pedestrian's gaze, gait, etc. In suchinstances, once a passenger is identified and determined to be lookingat the vehicle, the size of any additional information on the displaymay be increased. Location (e.g. GPS) and other signals such asBluetooth, from the passenger's client computing device could also beused as triggers to increase the size of the additional information.

In some instances, a passenger may be able to use his or her clientcomputing devices in order to cause the vehicle to change the display.For instance, a passenger may shake a client computing device (whichmight be detected using device accelerometers), press an on-screenbutton, use voice commands, etc. in order to have the vehicletemporarily flash or increase the brightness of the display or otherwiseshow different content. Those temporary changes could be dynamicallycomputed on the vehicle (for example using a time-based formula tocompute the brightness) and/or combined with pre-computed (either storedin memory at the vehicle or on a separate computing device) images withchanges in contrast or color, inverting of colors, motion, etc. Inaddition or alternatively, a passenger may be able to use theapplication to select from a predetermined set of sounds in order tocause the vehicle to play a sound (a ping, horn honk, melody, etc.) onan internal and/or an external speaker of the vehicle in order to assistthe passenger in locating the vehicle. In addition, the sound volume canbe influenced by user input. For example, shaking the passenger's clientcomputing device longer or faster will gradually increase the volume orloop (e.g. repeat) audio sound.

The display may also be used to provide other types of information suchas to signal status or intent. In this regard, the display may provideinformation about the vehicle's intent at unprotected intersections,when navigating in a parking lots, when staying parked for a while, whenpreparing to move after being parked for a while, when taking turns withother drivers in narrow passageways, responding to temporary roadblockages, when entering a school or construction zone, when waiting forpedestrians (e.g. to cross), when waiting for oncoming traffic to clear,when responding to a person directing traffic, responding to anemergency vehicle and/or pulling over, by displaying hazard or arrowindicators to encourage other vehicles to drive around the vehicle, whenacknowledging certain road users (i.e. that the vehicle “sees” apedestrian or a bicyclist, etc. In some instances, these notificationsmay be “humanized”, that is by using pronouns (e.g. my turn, I'm goingnext, etc.) or courtesies (e.g. please, thank you, etc.).

Other types of status information may be provided in notifications aswell. This may include, for example, operational cues or alerts relatingto battery or fuel status (e.g. low battery or low fuel), maintenanceissues and their priority (e.g. low priority or high prioritymaintenance issue), driving state (e.g. autonomous or manual mode),current task or assignment status (e.g. vehicles collecting map data ortesting may display different information than vehicles providingtransportation services or vehicles may be leaving or just arriving at adepot or other location for service). Status information might be shownon request when a technician is nearby and/or has requested suchinformation be shown for a limited time.

In addition, on high speed roads, such as those with speed limits at orabove 45 mph or more or less, the display may provide information thatis useful for broadcasting in high speed areas—with longer display timesto accommodate for messaging at higher speeds. Example messages may berelated to emergency signals, when the vehicle needs to broadcast aparticular state so other drivers might have enough time to adjust andreact safely. The vehicle may increase time to display communicationsprior to an event at higher speeds intent to pull over or that the carhas pulled over and is still slowing (i.e. still moving).

In other instances, a group of appropriately equipped vehicles maydisplay notifications in order to facilitate a technician finding aparticular vehicle. For instance, vehicles may “point to” anothervehicle in the group that is having issues for faster location of thatvehicle having the issues. This may involve a flashing arrow, othericon, emoticon, or emoji oriented in the direction of that vehicle orsequential information (3 more cars, then 2 more cars, etc.). Vehiclesmay also use the displays to broadcast information to one another orsignal a bigger message as a fleet. For example vehicles travelingtogether in a group might indicate approximately how much time until theentire group passes a given point. Or multiple vehicles could be used ina marriage proposal with each vehicle displaying one or a few words of asentence.

In addition, the display may be used to display notifications related topassengers such as when a passenger is being picked up or dropped off.For instance, a notification that a vehicle is ready to board might beshown to one or more sides of the vehicle while displaying a “boarding”icon to the rear of the vehicle for other vehicles or drivers toindicate that a passenger might be about to board, explaining that thecar is temporarily parked. Similarly, icons or other treatments(borders, inverse colors) may be used to indicate to a passenger when avehicle is ready for the passenger to board versus still approaching thepickup location or when the passenger's client computing device has notyet been authenticated (e.g. authentication may take place between thecomputing devices 110 and the passenger's client computing device.

Similarly, when the vehicle is stopped at a crosswalk with pedestrianscrossing, the vehicle may display a notification towards the front ofthe vehicle, “I'm stopped” or a pedestrian icon while to the rear of thevehicle may display a notification indicating that the vehicle iswaiting because pedestrians are crossing. This may enable passengers aswell as drivers (and potentially computers) of other vehicles tounderstand the vehicle's behavior. In this regard, for amultidirectional display or multiple displays, notifications can bedirectionally focused to multiple different viewers (e.g. pedestrians,vehicles, drivers, etc.) who are located in different directions.

On a vehicle capable of detecting and responding to passenger gestures,if a passenger were to gesture by waving to the vehicle, the displaymight confirm recognition of the gesture by providing information on thedisplay. For example, the display may indicate that the vehicle sees thepassenger, and if the passenger were to gesture or otherwise motion tothe vehicle to come to where the rider indicates, the display wouldrespond by indicating the intention to respond to the gesture, forinstance, by indicating that the vehicle is heading over, etc.Similarly, the display may respond to gestures of non-passengers wavinghello by showing a message like ‘Hi there’ or the like.

The features described herein may enable an autonomous vehicle tocommunicate with persons outside of the vehicle. In particular, thefeatures described herein may allow a vehicle to display information inorder to better enable those passengers to recognize the vehicle in away that is both practical and efficient.

Unless otherwise stated, the foregoing alternative examples are notmutually exclusive, but may be implemented in various combinations toachieve unique advantages. As these and other variations andcombinations of the features discussed above can be utilized withoutdeparting from the subject matter defined by the claims, the foregoingdescription of the embodiments should be taken by way of illustrationrather than by way of limitation of the subject matter defined by theclaims. In addition, the provision of the examples described herein, aswell as clauses phrased as “such as,” “including” and the like, shouldnot be interpreted as limiting the subject matter of the claims to thespecific examples; rather, the examples are intended to illustrate onlyone of many possible embodiments. Further, the same reference numbers indifferent drawings can identify the same or similar elements.

1. A method of displaying notifications on a display of an autonomousvehicle, the method comprising: determining, by one or more processorsof the vehicle, when the vehicle is between a first distance and asecond distance of a location, the location being a destination for thevehicle or a location of a passenger; when the vehicle is determined tobe between the first distance and the second distance of the location,displaying, by the one or more processors, on the display a firstnotification, the second distance being less than the first distance;determining, by one or more processors of the vehicle, when the vehicleis less than the second distance from the location; and when the vehicleis determined to be less than the second distance from the location,displaying, by the one or more processors, on the display a secondnotification, wherein the second notification provides additionalinformation not provided by the first notification.
 2. The method ofclaim 1, wherein the first notification includes a color whichidentifies the vehicle to the passenger.
 3. The method of claim 2,wherein the first notification does not include alphanumeric characters.4. The method of claim 2, wherein the second notification includes thecolor with alphanumeric characters, wherein the alphanumeric charactersprovide the additional information.
 5. The method of claim 2, whereinthe second notification includes the color with one or more icons,wherein the one or more icons provide the additional information.
 6. Themethod of claim 1, wherein the distance is the distance to thepassenger, and wherein the distance is determined based on locationinformation determined at a client computing device of the passenger. 7.The method of claim 1, wherein the first notification is brighter thanthe second notification.
 8. The method of claim 1, wherein the secondnotification is brighter than the first notification.
 9. The method ofclaim 1, further comprising, determining a brightness of the first orthe second notification based on the distance, and wherein displayingthe first notification is further based on the brightness.
 10. Themethod of claim 1, further comprising, determining a brightness of thefirst notification or the second notification based on current trafficconditions, and wherein displaying the first notification is furtherbased on the brightness.
 11. The method of claim 1, further comprising,determining a brightness of the first or the second notification basedcurrent weather conditions, and wherein displaying the firstnotification is further based on the brightness.
 12. The method of claim1, wherein displaying the first notification is further based on acurrent speed of the vehicle.
 13. The method of claim 1, whereindisplaying the second notification is further based on a current speedof the vehicle.
 14. The method of claim 1, further comprisingdetermining one or both of the first or second distances based oncontext in which the vehicle is driving.
 15. The method of claim 14,wherein the context includes a current speed of the vehicle.
 16. Themethod of claim 14, wherein the context includes a number of passengerswaiting for a pickup.
 17. The method of claim 14, wherein the contextincludes a number of vehicles picking up or dropping off a passenger.18. The method of claim 14, wherein the context includes current trafficconditions.
 19. The method of claim 1, further comprising, receiving arequest to change the display of the first or the second notification.20. The method of claim 19, further comprising, in response to therequest, flashing the display.
 21. The method of claim 20, furthercomprising, in response to the request, increasing a brightness of thedisplay.